Britons should not shy away from sunshine in summer and should take a daily supplement of vitamin D in winter in order to address serious levels of deficiency, experts say.

Leading doctors and researchers said that more than 60 per cent of the population have “sub-optimal” levels of the vitamin, with the problem being worse in Scotland, the North of England and among ethnic minorities.

Ahead of a major conference on vitamin D and health in London next week, they said people are putting their health at risk because they spend too little time in the sun, possibly because of fears over skin cancer.

Vitamin D, produced naturally when the skin is exposed to sunlight, plays a key role in strengthening bones and can help prevent fractures in the elderly. But there is emerging evidence that it can help prevent a range of other conditions, including asthma, type 2 diabetes and multiple sclerosis.